software
studio
structure of the web
Daniel Jackson
1
resources
resource has
› name
› location
› representation
2
URI, URN, URL?
what do they mean?
› URL: uniform resource location
› URN: uniform resource name
› URI: uniform resource identifier
URI = URL ∪ URN
does this matter?
› strictly speaking, browser gives server a URI
› content negotiation may turn it into a URL
my opinion
› just as in programming languages, names can expose
representation and location
3
URI structure
http://sdg.csail.mit.edu/projects.html
scheme
domain name
file path
http://bank.com/dep?acct=12&amt=10
action
4
query string
HTML and CSS
markup languages
› SGML was the earliest (1974)
› separation of semantics & presentation
HTML added
› interaction: fields, forms, scrollbars, etc
› hypertext: links
5
links and anchors
anchor
› a resource or an element within a document
link
› connection from a source to a destination anchor
7
link graphs of the web
mit.edu
8
csail.mit.edu
from: http://www.aharef.info
relative URIs
relative URI
› no scheme
› no domain name
› relative path
type in a JavaScript console:
console.log(document.baseURI)
base URI
› used to resolve it
examples
› base URI: http://www.acme.com/intro.html
› <a href="suppliers.html">Suppliers</a>
› resolves to http://www.acme.com/suppliers.html
who resolves? browser or server?
9
MIT OpenCourseWare
http://ocw.mit.edu
6.170 Software Studio
Spring 2013
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